JPH0872672A - Electronic key device and vehicle anti-theft system using it - Google Patents

Abstract

PURPOSE: To provide an electronic key device and a vehicle anti-theft system capable of obtaining the equivalent effect that the rolling of the code to be delivered and collated between a key body and a key receiving device is realized with the simplified logic. CONSTITUTION: A plurality of corresponding codes and the corresponding address information are stored in a key body 1 and a key receiving device 2, and the readout signal where the randomly changed address for each communication is designated is transmitted to the key body 1, and the key body 1 replies the code corresponding to the received address to the key receiving device 2. The key receiving device 2 compares the replied code with the code of the designated address, and the prescribed action is achieved based on the result of the comparison.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic key device and a vehicle antitheft device using the same, and in particular, a code signal is transmitted and received between a key body and a key receiving device, and a predetermined operation is performed based on the comparison result. The present invention relates to a permitting electronic key device and a vehicle theft prevention device using the electronic key device.

[0002]

2. Description of the Related Art Conventionally, in an electronic key device and a vehicle antitheft device using the electronic key device, when a key is inserted into a key cylinder and an engine is started, a specific data stored in the key is stored by data communication. The code signal is read out and verified by the controller on the key cylinder side. If the code is correct, the engine controller is allowed to start the engine, and if it is incorrect, the engine is not allowed to start. Is known (see, for example, Japanese Patent Laid-Open No. 5-39767). In such a device, the key side and the controller side each have a specific code to be collated, and if the code signal is always the same, it is easy to be intercepted, the code is analyzed, and the code is transmitted. If the key is duplicated, the vehicle may be stolen. Therefore, in order to solve this problem, there is a method in which the codes held by the keys and the key cylinders are rolled (changed) so that different code signals are communicated each time.

[0003]

However, in order to roll (change) the code as described above, it is necessary to memorize what is the code to be communicated next time in both the key body and the key receiving device. However, there is a problem in that logic is required to store the code. The present invention has been made to solve the above-mentioned problems, and a plurality of codes and corresponding addresses are provided between the key body and the key receiving device,
By enabling the rolling action of the code only by changing the address of the code to be read on the key receiving device side, the logic of the key receiving device and the key body can be simplified, and the code is analyzed and the vehicle is stolen. It is an object of the present invention to provide an electronic key device capable of preventing such a situation and a vehicle theft prevention device using the electronic key device.

[0004]

In order to achieve the above object, the invention of claim 1 is a key body having a storage unit storing a plurality of codes, and a key having a storage unit storing a plurality of codes. In the electronic key device that includes a receiving device and performs a predetermined operation based on the comparison result of the code of the key body and the code of the key receiving device, the key body and the storage unit of the key receiving device have a plurality of codes respectively. The corresponding address is stored, the key receiving device transmits a signal designating the address of the key body randomly or according to a predetermined rule, and the key body sends the code corresponding to the address designated by the key receiving device. It returns to the key receiving device, and the key receiving device compares the code returned from the key body with the code corresponding to the address designated by the key receiving device, and the comparison result Based in performs a predetermined operation. According to a second aspect of the present invention, in the electronic key device according to the first aspect, the key receiving device is provided with a key insertion opening for inserting the key body, and when the key body is inserted into the key insertion opening, the key reception is performed. An address is designated from the device to the key body. According to a third aspect of the present invention, in the electronic key device according to the first aspect, the key receiving device is provided with a key insertion opening for inserting the key body, and the key body is inserted in the key insertion opening. The code returned from is compared with the code stored in the storage unit of the key receiving device. Further, the invention of claim 4 is a vehicle antitheft device comprising the electronic key device according to any one of claims 1 to 3, wherein the code returned from the key body and the key receiving device are provided. Based on the comparison result with the code stored in, the starting of the engine of the vehicle is permitted or prohibited. According to the invention of claim 5, in the electronic key, a plurality of codes and storage means for storing address information corresponding to the codes, a receiving means for receiving address information from the outside, and a receiving means are received. And a transmission means for transmitting the code stored in the storage means corresponding to the address information. The invention of claim 6 is the key receiving device,
The storage means stores a plurality of codes corresponding to the address information, the transmission means for transmitting the address information to the outside at random or according to a predetermined rule, the reception means for receiving the codes from the outside, and the storage means. Comparing means for comparing the code corresponding to the stored address information with the external code received by the receiving means, and control means for permitting or prohibiting a predetermined operation based on the comparison result by the comparing means. It is a thing.

[0005]

According to the first aspect of the present invention having the above structure, when the codes are collated by the key body and the key receiving device,
The address of the code to be read is designated by the key receiving device side according to a random or predetermined rule, and is transmitted to the key body side. The key body side reads the code corresponding to the received address and sends it back to the key receiving device side. The key receiving device compares the received code with the stored code, and determines whether to permit execution of a predetermined operation based on the comparison result. As described above, the read address transmitted from the key receiving device side changes every time the collation is performed, and the same operation as that of rolling the code can be obtained. According to the second aspect of the invention, when the key body is inserted into the key insertion opening of the key receiving device, the key receiving device specifies the address of the code to be read from the key body. .
Further, according to the invention of claim 3, when the key body is inserted in the key insertion opening of the key receiving device, the code read from the storage unit in the key body and returned and the memory of the key receiving device. A comparison is made with the code stored in the department. Further, according to the invention of claim 4, based on the comparison result of the codes by the electronic key device, it is possible to permit or prohibit the starting of the engine and prevent theft. Further, according to the invention of claim 5, when the address is transmitted from an external key receiving device, for example, the address is received by the receiving means of the electronic key and stored in the storage means corresponding to this address. The code is read. The code is returned to the key receiving device side by the transmitting means. Further, according to the invention of claim 6, when an attempt is made to collate a code between the key receiving device and an external electronic key, the address of the code to be read is designated by the transmitting means and transmitted to the electronic key. To be done. After that, the code returned from the electronic key is received by the receiving means, and this code and the code corresponding to the address stored in the storage means of the key receiving device are compared by the comparing means. Based on the comparison result, the control means determines whether or not the predetermined operation is permitted.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an electronic key device and a vehicle antitheft device using the electronic key device. The electronic key device includes a key body 1 and a key receiving device 2 that receives the key body 1. The key body 1 is a mechanical key 1
a, a storage device 3 made of an EEPROM or the like for storing a plurality of codes and addresses corresponding thereto, which is built in the knob portion, a receiving circuit 4 for receiving an address signal transmitted from the key receiving device 2, and a key receiving device. It comprises a transmission circuit 5 for transmitting a code signal to the device 2 and an antenna 6 for transmitting and receiving the address signal and the code signal.

The key receiving device 2 is composed of a key cylinder 2a into which the mechanical key 1a is inserted, an antenna 7 provided near the key cylinder 2a, and a controller 8.
The antenna 7 has a mechanical key 1a and a key cylinder 2a.
When it is inserted into the key body 1, it is electromagnetically coupled to the antenna 6 of the key body 1 to supply electric power from the key receiving device 2 side to the key body 1 side, and to exchange a signal including code information. Note that the key receiving device 2 is supplied with power from a battery.

The controller 8 includes a transmitter circuit 9 for transmitting an address signal to the key body 1, a receiver circuit 10 for receiving a code signal from the key body 1, and a storage device 3 of the key body 1.
The storage device 12 is composed of an EEPROM or the like for storing a plurality of codes and the addresses corresponding to the codes, and a central processing unit (hereinafter referred to as CPU) 11 that controls the key receiving device 2. The CPU 11 sends and receives signals to and from the transmission circuit 9 and the reception circuit 10, and designates an address signal to be read from the storage device 3 of the key body 1 and returns from the key body 1 side. A comparison between the code signal and the code signal of the storage device 12 on the key receiving device 2 side;
Based on the comparison result, processing for permitting or prohibiting execution of a predetermined operation is performed, and a control signal is output to the engine controller 13.

FIG. 2 is a flow chart showing the flow of processing of the electronic key device. The process flow will be described below with reference to FIG. In this process, the electronic key functions as a vehicle antitheft device when the engine of the vehicle is about to be started. In this process, the CPU 11 checks whether or not the mechanical key 1a is inserted into the key cylinder 2a (# 1).
When a is inserted into the key cylinder 2a (YE in # 1
S), the antenna 6 and the antenna 7 are electromagnetically coupled, and electric power is supplied from the key receiving device 2 side to the key body side 1. It should be noted that the detection of the insertion of the key may be performed by a key detection switch (not shown) provided on the key receiving device 2 side.

Next, the CPU 11 randomly changes the address of the code to be read from the storage device 3 on the side of the key body 1 every time it is read and specifies it (#
2). It is desirable to make this change by generating a random number, but according to a predetermined rule,
It is sufficient that the changed address cannot be predicted from the unchanged address, and it is not necessarily limited to the one by generating a random number. Next, the address is transmitted from the transmitting circuit 9 in the key receiving device 2 to the receiving circuit 4 via the antenna 7 and the antenna 7 in the key body 1 (# 3). Here, in the present invention, the code itself to be read is not transmitted, but the address corresponding thereto is transmitted.
The key body 1 selects a code stored in the storage device 3 corresponding to the address received by the receiving circuit 4, and returns the code to the key receiving device 2 side via the antenna 6 by the transmitting circuit 5 (# 4).

The receiving circuit 10 in the controller 8 in the key receiving device 2 receives a reply from the key body 1 side via the antenna 7, and the CPU 11 sends the returned code and the above-mentioned transmitted address. Storage device 12 corresponding to
And compare it with the code stored in to determine whether the returned code is correct (#
5). When the CPU 11 determines that the code is correct, the engine start is permitted (# 6), and when the code is incorrect, the engine start is prohibited (# 7). Examples of the operation of prohibiting the start of the # 7 engine include the operation of not turning on the starter, shutting off the fuel supply to the engine, or turning off the ignition switch. Any operation that can be prohibited may be used, and the operation is not limited to a specific operation.

By performing the above-described processing, the code collated between the key body 1 side and the key receiving device 2 side each time the engine is started is provided with the same function as that of the rolled code. For this reason, it is not necessary to store the code to be collated next time on the key body side and the key receiving device side as in the conventional case, so that the logic on the key body side can be particularly simplified. Further, since the key receiving device transmits not the code to be verified but the address changed for each communication, it is possible to prevent the vehicle from being stolen by analyzing the communication code.

The present invention is not limited to the configuration of the above embodiment, but various modifications can be made. For example, in the above embodiment, the key receiving device 2 supplies electric power to the key body 1 by electromagnetic coupling, but instead of this, a battery may be built in the key body 1 side. Further, for data communication between the two, radio waves or light may be used in addition to the one using electromagnetic coupling.

[0014]

As described above, according to the electronic key device of the present invention and the vehicle antitheft device using the electronic key device, a plurality of corresponding codes and addresses corresponding thereto are stored in the key body and the key receiving device. Then, the address of the code to be read from the key receiving device side is rolled, and the code corresponding to the address is returned from the key body side. It is not necessary to store it on the key receiving device side, and the same effect as that of rolling the code can be obtained only by determining the address to be read next time on the key receiving device side. Therefore, in particular, the logic on the key body side can be simplified and the cost can be reduced as compared with the related art.
Moreover, since the code to be collated is changed for each communication by rolling the address instead of rolling the code itself, it is possible to prevent the communication code from being analyzed and the vehicle being stolen.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an electronic key device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing flow of the electronic key device.

[Explanation of symbols]

 1 Key Main Body 2 Key Receiving Device 2a Key Cylinder (Key Insertion Port) 3 Storage Device (Storage Means) 4 Reception Circuit 5 Transmission Circuit 9 Transmission Circuit 10 Reception Circuit 11 Central Processing Unit 12 Storage Device (Storage Means) 13 Engine Controller

Claims (6)

[Claims] 1. A key main body having a storage unit storing a plurality of codes, and a key receiving device having a storage unit storing a plurality of codes, the code of the key main body and the code of the key receiving device. In an electronic key device that performs a predetermined operation based on a comparison result with, the key body and the storage unit of the key receiving device, the addresses corresponding to the plurality of codes are respectively stored, the key receiving device, Transmitting a signal designating the address of the key body at random or according to a predetermined rule, the key body returning a code corresponding to the address designated by the key receiving device to the key receiving device, The receiving device compares the code returned from the key body with the code corresponding to the address designated by the key receiving device, and based on the comparison result, a predetermined value is determined. Electronic key device and performs the operation. 2. The key receiving device is provided with a key insertion opening for inserting the key main body, and when the key main body is inserted into the key insertion opening, an address is designated from the key receiving device to the key main body. The electronic key device according to claim 1, wherein: 3. A key receiving device is provided with a key insertion port for inserting a key body, and when the key body is inserted in the key insertion port, the code returned from the key body and the key receiving device The electronic key device according to claim 1, wherein a comparison with a code stored in the storage unit is performed. 4. A vehicle antitheft device comprising the electronic key device according to any one of claims 1 to 3, wherein a code returned from the key body and a storage unit in the key receiving device are provided. A vehicle antitheft device, which permits or prohibits starting of an engine of the vehicle based on a comparison result with a stored code. 5. A storage means for storing a plurality of codes and address information corresponding to the codes, a receiving means for receiving address information from the outside, and the storage corresponding to the address information received by the receiving means. An electronic key comprising a transmitting means for transmitting a code stored in the means. 6. Storage means in which a plurality of codes are stored in correspondence with address information, transmission means for transmitting address information to the outside at random or according to a predetermined rule, and receiving means for receiving codes from the outside. And comparing means for comparing a code corresponding to the address information stored in the storing means with an external code received by the receiving means, and permitting a predetermined operation based on the comparison result by the comparing means. Or a key receiving device provided with a prohibiting control means.